sapogenins and Breast-Neoplasms

Natural products have documented oncology success history as valuable scaffolds for selective target modulation. Herein, the sapogenin hecogenin (1) was screened for its anti-breast cancer inhibitory capacity using in vitro assays, including proliferation, cytotoxicity, migration, invasion assays, and Western blotting. The results identified 1 as a propitious hit with modest activities attributed to the concurrent down-regulation of mitogen activated protein kinase kinase/extracellular signal-regulated kinase (MEK) distinctive downstream effectors. Guided by in silico 3D-structural insights of MAPK kinase domain, an extension strategy was adopted at 1's C-3 and C-12 aimed at the design of novel hecogenin-based analogs with improved target binding affinity. Thirty-three analogs were prepared and tested, among which hecogenin 12-(3'-methylphenyl thiosemicarbazone) (30) displayed the most potent selective anticancer effects. Analog 30 demonstrated antiproliferative, antimigratory and anti-invasive activities at low μM level, compared to the negligible effect on the non-tumorigenic MCF-10A mammary epithelial cells. Durable regression of breast tumor xenografts in athymic nude mice was observed after treatments with 30, compared to its parent hecogenin at the same dose regimen, confirmed the hit-to-lead promotion of this analog. Hecogenin-12-thiosemicarbazones, represented by 30, is a novel MEK inhibitory lead class to control breast neoplasms.

Topics: Animals; Antineoplastic Agents; Breast Neoplasms; Cell Proliferation; Dose-Response Relationship, Drug; Drug Design; Drug Screening Assays, Antitumor; Female; Humans; Mammary Neoplasms, Experimental; MAP Kinase Kinase Kinases; Mice; Mice, Nude; Molecular Structure; Protein Kinase Inhibitors; Sapogenins; Structure-Activity Relationship; Thiosemicarbazones; Tumor Cells, Cultured

While the incidence of cancer continues to increase, the current therapeutic options remain imperfect. Therefore, there is an urgent need to discover new targeted anti-cancer therapies. Testes-specific protease 50 (TSP50) is abnormally expressed in most cancer tissues and downregulation of TSP50 expression can reduce cell proliferation and induce cell apoptosis, which makes it a potential target for cancer therapy. In this study, we constructed a firefly luciferase reporter pGL3-TSP50-3'-UTR as a drug screening model to screen potential candidate compounds that target TSP50 mRNA. We identified the compound 7P3A, which consists of 70 % 25-methoxyl-dammarane-3β, 12β, 20-triol and 30 % artemisinin, as being capable of inhibiting the TSP50-3'-UTR reporter activity, as well as the expression of TSP50. Further investigation revealed that 7P3A could inhibit MDA-MB-231 cell proliferation and induce cell cycle arrest, and over-expression of TSP50 partially reversed the effect of 7P3A. In vivo investigation showed that 7P3A could inhibit tumor growth in a xenograft model of breast cancer. These results suggest that 7P3A exhibits anti-cancer effects, in part, through downregulation of TSP50 expression.

Topics: 3' Untranslated Regions; Animals; Antimalarials; Antineoplastic Combined Chemotherapy Protocols; Artemisinins; Blotting, Western; Breast Neoplasms; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Drug Synergism; Female; Gene Expression Regulation, Neoplastic; Humans; MCF-7 Cells; Mice, Inbred BALB C; Mice, Nude; Reverse Transcriptase Polymerase Chain Reaction; Sapogenins; Serine Endopeptidases; Tumor Burden; Xenograft Model Antitumor Assays

20(S)-Protopanaxadiol (PPD), a ginsenoside isolated from Pananx quinquefolium L., has been shown to inhibit growth and proliferation in several cancer cell lines. The aim of this study was to evaluate its anticancer activity in human breast cancer cells. MCF-7 cells were incubated with different concentrations of 20(S)-PPD and cytotoxicity was evaluated by MTT assay. Occurrence of apoptosis was detected by DAPI and Annexin V-FITC/PI double staining. Mitochondrial membrane potential was measured with Rhodamine 123. The Bcl-2 and Bax expression were determined by Western blot analysis. Caspase activity was measured by colorimetric assay. 20(S)-PPD dose-dependently inhibited cell proliferation in MCF-7 cells, with an IC50 value of 33.3 μM at 24h. MCF-7 cells treated with 20(S)-PPD presented typical apoptosis, as observed by morphological analysis in cell stained with DAPI. The percentages of annexin V-FITC positive cells were 8.92%, 17.8%, 24.5% and 30.5% in MCF-7 cells treated with 0, 15, 30 and 60μM of 20(S)-PPD, respectively. Moreover, 20(S)-PPD could induce mitochondrial membrane potential loss, up-regulate Bax expression and down-regulate Bcl-2 expression. These events paralleled activation of caspase-9, -3 and PARP cleavage. Apoptosis induced by 20(S)-PPD was blocked by z-VAD-fmk, a pan-caspase inhibitor, suggesting induction of caspase-mediated apoptotic cell death. In conclusion, the 20(S)-PPD investigated is able to inhibit cell proliferation and to induce cancer cell death by a caspase-mediated apoptosis pathway.

Topics: Antidepressive Agents; Apoptosis; Blotting, Western; Breast Neoplasms; Caspases; Cell Proliferation; Cytochromes c; Female; Humans; Membrane Potential, Mitochondrial; Mitochondria; Sapogenins; Signal Transduction; Tumor Cells, Cultured

Protopanaxadiol (PPD), an aglycon of ginseng saponins, has shown anticancer activity in earlier studies. Here, we have reported the semisynthesis of nine PPD derivatives with acetyl substitutions. Subsequently, the antiproliferative effects of these nine analogs on different human cancer cell lines have been investigated. Compounds 1, 3, and 5 showed more significant and more potent antiproliferative activity compared with PPD and other derivatives. A flow cytometric assay indicated that compounds 1, 3, and 5 arrested cell cycle progression in the G1 phase and significantly induced apoptosis of cancer cells.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Breast Neoplasms; Cell Growth Processes; Cell Line, Tumor; Colorectal Neoplasms; Drug Screening Assays, Antitumor; Female; G1 Phase; HCT116 Cells; Humans; Magnetic Resonance Spectroscopy; Panax; Sapogenins; Saponins; Structure-Activity Relationship

A new cephalostatin/ritterazine analogue was prepared from the commercially available hecogenin acetate and the natural cytotoxic steroid 22-epi-hippuristanol. The method involved the reductive dimerization of enaminoketones (condensation of alpha-aminoketones) and condensation between an enaminoketone and an alpha-hydroxyketone. The new analogue showed higher cytotoxic activity than the cytotoxic 22-epi-hippuristanol against MDA-MB-231, A-549 and HT-29 cultured tumor cell lines.

Topics: Antineoplastic Agents; Breast Neoplasms; Carcinoma; Cell Line, Tumor; Cell Proliferation; Colorectal Neoplasms; Cytotoxins; Female; Humans; Inhibitory Concentration 50; Lung Neoplasms; Phenazines; Sapogenins; Spiro Compounds; Steroids; Sterols

20S-protopanaxadiol (aPPD) is a major gastrointestinal metabolic product of ginsenosides. The latter share structural similarity with steroids and are the main pharmacologically active component in ginseng.. The authors investigated the interaction between aPPD and estrogen receptors (ER) in human breast adenocarcinoma MCF-7 cells through receptor binding assay, ER-induced gene expression, and cell proliferation both in vitro and in vivo.. aPPD, but not its close analog ginsenosides, competed with the [(3)H]-17-beta estradiol (E2) for ER with IC(50) at 26.3 microM. aPPD alone weakly induced luciferase reporter-gene expression controlled by an estrogen-regulated element, which was completely blocked by tamoxifen. aPPD alone, or in synergy with tamoxifen, blocked E2-induced transcriptional activation. aPPD also inhibited colony formation of endometrial cancer cells. aPPD potently inhibited estrogen-stimulated MCF-7 cell proliferation and synergistically enhanced the cytotoxicity of tamoxifen on both ER+ MCF-7 and ER- MDA-MB231 cells. Furthermore, aPPD, but not tamoxifen, inhibited Akt phosphorylation. Growth of MCF-7 xenograft tumor supplemented with E2 was completely inhibited in animals treated with aPPD, tamoxifen, or aPPD plus tamoxifen.. These results suggested that aPPD inhibits estrogen-stimulated gene expression and cell proliferation in ER-positive breast cancer cells. In addition, aPPD synergistically enhances cytotoxicity of tamoxifen in an ER-independent fashion, probably by down-regulating Akt activity.

Topics: Adenocarcinoma; Animals; Blotting, Western; Breast Neoplasms; Cell Proliferation; Drug Synergism; Estrogen Antagonists; Female; Humans; Mice; Mice, SCID; Panax; Phosphorylation; Proto-Oncogene Proteins c-akt; Receptors, Estrogen; Sapogenins; Tamoxifen; Transplantation, Heterologous; Triterpenes; Tumor Cells, Cultured

Recently, a novel intestinal bacterial metabolite of ginseng protopanaxadiol saponins, i.e., 20-O-(beta-D-glucopyranosyl)-20(S)-protopanaxadiol (IH-901), has been reported to induce apoptosis in a variety of cancer cells. Here we show a differential effect of IH-901 on several cell types. Exposure to IH-901 for 48 hours at a supposedly subapoptotic concentration of 40 mumol/L led to both apoptotic cell death and G1 arrest in Hep3B cells, but only resulted in G1 arrest in MDA-MB-231, Hs578T, and MKN28 cells. Additionally, the treatment of MDA-MB-231, but not of Hep3B, with IH-901 up-regulated cyclooxygenase-2 (COX-2) mRNA (2 hours) and protein (6 hours), and enhanced the production of prostaglandin E2. In MDA-MB-231 cells, IH-901 induced the sustained activation of extracellular signal-regulated kinase (ERK), whereas inhibition of mitogen-activated protein/ERK kinase blocked IH-901-mediated COX-2 induction and resulted in apoptosis, suggesting the involvement of an ERK-COX-2 pathway. Combined treatment with IH-901 and nonsteroidal anti-inflammatory drugs inhibited COX-2 enzyme and induced apoptosis in MDA-MB-231 and Hs578T cells. Adenovirus-mediated COX-2 small interfering RNAs also effectively inhibited COX-2 protein expression and enhanced IH-901-mediated apoptosis without inhibiting ERK 1/2 phosphorylation, thus providing direct evidence that COX-2 is an antiapoptotic molecule. Moreover, IH-901-mediated G1 arrest resulted from an increase in p27Kip1 mRNA and protein expression followed by a decrease in CDK2 kinase activity that was concurrent with the hypophosphorylation of Rb and p130. In conclusion, IH-901 induced both G1 arrest and apoptosis, and this apoptosis could be inhibited by COX-2 induction.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Breast Neoplasms; Carcinoma, Hepatocellular; Carrier Proteins; CDC2-CDC28 Kinases; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase Inhibitor p27; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Extracellular Signal-Regulated MAP Kinases; G1 Phase; Humans; Intracellular Signaling Peptides and Proteins; Liver Neoplasms; Membrane Proteins; Phosphorylation; Prostaglandin-Endoperoxide Synthases; Proteins; Retinoblastoma Protein; Retinoblastoma-Like Protein p130; RNA, Messenger; RNA, Small Interfering; Sapogenins; Tumor Cells, Cultured